Purpose: :
On average, African Americans have a central corneal thickness(CCT) 30 microns less than Caucasians. More than a mere anatomicalcuriosity, differences in CCT contribute to an important healthdisparity issue. CCT is an independent risk factor for glaucoma.Here, we initiate genetic studies to analyze the basic biologyof CCT with a quantitative trait association approach utilizinginbred strains of mice.

Methods: :
Murine CCT was measured with an ultrasound pachymeter and reliabilitytested by comparing pachymetry measurements to measurementsfrom unfixed cryosections. A strain survey was performed with17 different inbred strains of mice. Corneas from three strainswith non-overlapping differences in CCT (C57BLKS/J, C57BL/6J,and SJL/J) were compared by histology, TEM, and expression profilingwith gene microarrays. The thinnest (C57BLKS/J) and thickest(SJL/J) strains were intercrossed, producing 225 F2 mice. Thesemice were phenotyped, the 20% extremes were genotyped, and associationswere detected using interval-mapping to assign probabilities.